NEW YORK, July 23 (Xinhua) -- U.S. star swimmer Ryan Rochte has been banned 14 months for receiving intravenous infusion, the U.S. Anti-Doping Agency (USADA) announced on Monday.

Rochte said that he was receiving vitamins, a permitted substance, to enhance his immune system as his wife and child were both ill. But the amount he took was over 100 milliliters and he had no "therapeutic use" exemption for the infusion, which constituted a anti-doping violation, the USADA explained.

"A rule is a rule and I accept that there is a technical violation," Lochte said, acknowledging his misbehavior. "I am hopeful other athletes will learn from my mistake and be mindful of this rule, as well as others."

The investigation started after Rochte posted a photo of himself receiving intravenous infusion on his social media on May 24.

The suspension, retroactive to the day he posted, will last till July, 2019, which means the 12-time Olympic medalist will miss the upcoming U.S. championship in California and world championships next year.